BAGHDAD -- Dozens of gunmen swooped into a police chief's home Friday, killing his wife and two brothers and kidnapping three of his grown children. The senior officer wasn't there, but the bold attack provided a grisly example of the dangers facing Iraqi forces as they try to take over the country's security so American forces can leave.

The attackers, armed with machine guns and rifles, drove up at 6:30 a.m., then battled their way into Col. Ali Dilayan al-Jorani's house on the outskirts of Baqouba, in Diyala province 35 miles northeast of the capital, according to officers at the provincial police center. Eleven guards also were killed, they said.

They said the attackers arrived in "many cars" and abducted two sons and a daughter of al-Jorani, head of central Baqouba's Balda police station. The officers spoke on condition of anonymity because they feared they would be next.

Iraqi police are frequent targets of al-Qaida-linked insurgents bent on ending cooperation between government security forces and U.S. troops in Baghdad and surrounding areas.

At least 751 Iraqi security personnel have been killed since a U.S.-Iraqi security crackdown began on Feb 14. During the same length of time immediately preceding Feb. 14, at least 593 Iraqi security personnel were killed, according to figures compiled by The Associated Press. The actual number in both cases is likely higher as many killings go unreported or uncounted.

The U.S. military recently acknowledged that the rampant violence had forced it divert some attention from training Iraqi troops, who the Americans hope will be ready to assume the fight when American forces pull back.

Diyala province, a hotbed of the Sunni insurgency, has become increasingly dangerous since the beginning of the Baghdad security operation nearly four months ago.

Militants have fled the capital to avoid capture and forced the U.S. military to dispatch about 3,000 more American forces to Diyala from already overtaxed reinforcements arriving in Baghdad.

But the attack on the police chief's home was one of the boldest and bloodiest in months of violence. It also coincided with the shift in loyalty of some Sunni insurgent fighters, who have joined the fight against al-Qaida.

A policeman, who spoke on condition of anonymity because he feared reprisal attacks, said al-Jorani is a Sunni. He said many officers from both Islamic sects have sent their families either outside the province or in some cases, outside the country, and are living in their offices for fear of al-Qaida, which he said is feeling increased pressure as other insurgent groups turn against it in the area.

Tensions also rose on the outskirts of Diyala's Shiite enclave of Khalis, where dozens of suspected insurgents were gathering and police called for U.S. and Iraqi army assistance, according to Maj. Gen. Ghanim al-Qureyshi, the head of the Diyala provincial police.

Bombings also struck to the north and the south of the capital as at least 77 Iraqis were killed nationwide.

Worshippers leaving Friday prayers at a Shiite mosque in Dakok, near the oil-rich northern city of Kirkuk, were struck by a parked car bombing that killed at least 19 people, police Brig. Gen. Sarhat Qadir said.

About five minutes later, a suicide bomber was spotted driving toward the mosque but police in a nearby station opened fire on him and he exploded, Qadir said. At least 25 people were wounded in the twin attacks, most in the parked car bomb.

Um Zainab, a 52-year-old housewife whose son was seriously wounded, blamed Sunni insurgents for the blast and called them traitors to Islam.

"They want to kill people even when they are praying in a mosque," she said as she stood in the hospital waiting for her son to come out of surgery. "Nobody wants them in Iraq. What is the guilt of the believers who were practicing their religious duties?"

Murtada Saleh, a 62-year-old retiree, lives near the attacked Shiite mosque but said he quit going there to pray several months ago because he feared such an attack.

"I have a big family to feed and I do not want to be killed. I also have prevented my sons from going to the mosque," he said, adding that the windows in his house were shattered in the blast. "We are a religious family, but one should be cautious."

Kirkuk, 180 miles north of Baghdad, is the center of Iraq's northern oil fields and has seen a recent rise in ethnic tensions as Kurds seek to incorporate the city into their self-governing region, drawing the ire of many Sunni Arabs who live there.

A parked minibus exploded at a terminal in the predominantly Shiite town of Qurnah, 300 miles southeast of Baghdad, and hospital officials said at least 16 people were killed and 32 wounded.

A witness, taxi driver Salim Abdul-Hussein, 35, said the blast damaged the bus terminal and many cars and surrounding shops, striking an area crowded each morning with farmers coming to town to shop and sell their produce and animals.

In Basra, the provincial capital 60 miles to the south, a minibus loaded with rockets, ammunition, C4 explosives and benzene blew up and caused a nearby car to explode in flames, said the police chief, Maj. Gen. Mohammed Hammadi. Police cordoned off the area and arrested two Egyptian suspects, he said.

At Qurnah hospital, director Ali Qassim told the AP by telephone that the medical facility had received 16 bodies from the explosions and 32 wounded.